edu.illinois.cs.cogcomp.lbjava.infer

Class PropositionalDoubleImplication

java.lang.Object

edu.illinois.cs.cogcomp.lbjava.infer.Constraint

edu.illinois.cs.cogcomp.lbjava.infer.PropositionalConstraint

edu.illinois.cs.cogcomp.lbjava.infer.PropositionalBinaryConstraint

edu.illinois.cs.cogcomp.lbjava.infer.PropositionalDoubleImplication

All Implemented Interfaces:

Cloneable

public class PropositionalDoubleImplication
extends PropositionalBinaryConstraint

Represents a double implication between two propositional constraints.

Author:

Nick Rizzolo

Field Summary

Fields inherited from class edu.illinois.cs.cogcomp.lbjava.infer.PropositionalBinaryConstraint

left, right

Constructor Summary

Constructors

Constructor and Description
PropositionalDoubleImplication(PropositionalConstraint l, PropositionalConstraint r) Initializing constructor.

Method Summary

Modifier and Type	Method and Description
PropositionalConstraint	CNF() Produces a new, logically simplified version of this constraint in conjunctive normal form (CNF).
PropositionalConstraint	DNF() Produces a new, logically simplified version of this constraint in disjunctive normal form (DNF).
boolean	equals(Object o) Two PropositionalDoubleImplications are equivalent when they are topologically equivalent, respecting the commutativity of double implication.
boolean	evaluate() Determines whether the constraint is satisfied.
int	hashCode() The hash code of a PropositionalDoubleImplication is the sum of the hash codes of its children plus three.
boolean	moreGeneralThan(PropositionalConstraint c) Compares topology to determine if this constraint is more general than the given constraint; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalAtLeast c) Compares topology to determine if this constraint is more specific than the given at-least; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalConjunction c) Compares topology to determine if this constraint is more specific than the given conjunction; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalConstant c) Compares topology to determine if this constraint is more specific than the given constant; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalDisjunction c) Compares topology to determine if this constraint is more specific than the given disjunction; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalDoubleImplication c) Compares topology to determine if this constraint is more specific than the given double implication; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalImplication c) Compares topology to determine if this constraint is more specific than the given implication; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalNegation c) Compares topology to determine if this constraint is more specific than the given negation; note: this method is not required to be correct when it answers false.
boolean	moreSpecificThan(PropositionalVariable c) Compares topology to determine if this constraint is more specific than the given variable; note: this method is not required to be correct when it answers false.
PropositionalConstraint	negate() Produces a new propositional constraint equivalent to this constraint and that contains no negated constraints other than variables.
void	runVisit(Inference infer) Calls the appropriate visit(·) method of the given Inference for this Constraint, as per the visitor pattern.
PropositionalConstraint	simplify() Produces a new, logically simplified version of this constraint, preserving variable consolidation.
void	write(StringBuffer buffer) Creates a string respresentation of this constraint using the string representations of the objects involved.

Methods inherited from class edu.illinois.cs.cogcomp.lbjava.infer.PropositionalBinaryConstraint

consolidateVariables, getChildren

Methods inherited from class edu.illinois.cs.cogcomp.lbjava.infer.PropositionalConstraint

clone, toString

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

PropositionalDoubleImplication

public PropositionalDoubleImplication(PropositionalConstraint l,
                                      PropositionalConstraint r)

Initializing constructor.

Parameters:

l - The constraint on the left of the operator.

r - The constraint on the right of the operator.

Method Detail

evaluate

public boolean evaluate()

Determines whether the constraint is satisfied.

Specified by:

evaluate in class Constraint

simplify

public PropositionalConstraint simplify()

Produces a new, logically simplified version of this constraint, preserving variable consolidation.

Specified by:

simplify in class PropositionalConstraint

Returns:

A logically simplified version of this constraint.

See Also:

Constraint.consolidateVariables(java.util.AbstractMap)

negate

public PropositionalConstraint negate()

Produces a new propositional constraint equivalent to this constraint and that contains no negated constraints other than variables.

Specified by:

negate in class PropositionalConstraint

Returns:

A constraint representing the negation of this constraint.

CNF

public PropositionalConstraint CNF()

Produces a new, logically simplified version of this constraint in conjunctive normal form (CNF).

Specified by:

CNF in class PropositionalConstraint

Returns:

The conjunctive normal form of this constraint.

DNF

public PropositionalConstraint DNF()

Produces a new, logically simplified version of this constraint in disjunctive normal form (DNF).

Specified by:

DNF in class PropositionalConstraint

Returns:

The disjunctive normal form of this constraint.

moreGeneralThan

public boolean moreGeneralThan(PropositionalConstraint c)

Compares topology to determine if this constraint is more general than the given constraint; note: this method is not required to be correct when it answers false.

Specified by:

moreGeneralThan in class PropositionalConstraint

Parameters:

c - The given constraint.

Returns:

true if a topological analysis determined that this constraint is more general than the given constraint.

moreSpecificThan

public boolean moreSpecificThan(PropositionalImplication c)

Compares topology to determine if this constraint is more specific than the given implication; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given implication.

Returns:

true if a topological analysis determined that this constraint is more specific than the given implication.

moreSpecificThan

public boolean moreSpecificThan(PropositionalDoubleImplication c)

Compares topology to determine if this constraint is more specific than the given double implication; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given double implication.

Returns:

true if a topological analysis determined that this constraint is more specific than the given double implication.

moreSpecificThan

public boolean moreSpecificThan(PropositionalConjunction c)

Compares topology to determine if this constraint is more specific than the given conjunction; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given conjunction.

Returns:

true if a topological analysis determined that this constraint is more specific than the given conjunction.

moreSpecificThan

public boolean moreSpecificThan(PropositionalDisjunction c)

Compares topology to determine if this constraint is more specific than the given disjunction; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given disjunction.

Returns:

true if a topological analysis determined that this constraint is more specific than the given disjunction.

moreSpecificThan

public boolean moreSpecificThan(PropositionalAtLeast c)

Compares topology to determine if this constraint is more specific than the given at-least; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given at-least.

Returns:

true if a topological analysis determined that this constraint is more specific than the given disjunction.

moreSpecificThan

public boolean moreSpecificThan(PropositionalNegation c)

Compares topology to determine if this constraint is more specific than the given negation; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given negation.

Returns:

true if a topological analysis determined that this constraint is more specific than the given negation.

moreSpecificThan

public boolean moreSpecificThan(PropositionalVariable c)

Compares topology to determine if this constraint is more specific than the given variable; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given variable.

Returns:

true if a topological analysis determined that this constraint is more specific than the given variable.

moreSpecificThan

public boolean moreSpecificThan(PropositionalConstant c)

Compares topology to determine if this constraint is more specific than the given constant; note: this method is not required to be correct when it answers false.

Specified by:

moreSpecificThan in class PropositionalConstraint

Parameters:

c - The given constant.

Returns:

true if a topological analysis determined that this constraint is more specific than the given constant.

hashCode

public int hashCode()

The hash code of a PropositionalDoubleImplication is the sum of the hash codes of its children plus three.

Overrides:

hashCode in class Object

Returns:

The hash code for this PropositionalDoubleImplication.

equals

public boolean equals(Object o)

Two PropositionalDoubleImplications are equivalent when they are topologically equivalent, respecting the commutativity of double implication.

Overrides:

equals in class Object

Returns:

true iff the argument is an equivalent PropositionalDoubleImplication.

runVisit

public void runVisit(Inference infer)

Calls the appropriate visit(·) method of the given Inference for this Constraint, as per the visitor pattern.

Specified by:

runVisit in class Constraint

Parameters:

infer - The inference visiting this constraint.

write

public void write(StringBuffer buffer)

Creates a string respresentation of this constraint using the string representations of the objects involved.

Specified by:

write in class PropositionalConstraint

Parameters:

buffer - The output of this method will be appended to this buffer.